title: Atrial natriuretic Peptide single nucleotide polymorphisms in patients with nonfamilial structural atrial fibrillation.
abstract: BACKGROUND
  Atrial natriuretic peptide (ANP) has antihypertrophic and antifibrotic properties that are relevant to AF substrates. The -G664C and rs5065 ANP single nucleotide polymorphisms (SNP) have been described in association with clinical phenotypes, including hypertension and left ventricular hypertrophy. A recent study assessed the association of early AF and rs5065 SNPs in low-risk subjects. In a Caucasian population with moderate-to-high cardiovascular risk profile and structural AF, we conducted a case-control study to assess whether the ANP -G664C and rs5065 SNP associate with nonfamilial structural AF.
  
  
  METHODS
  168 patients with nonfamilial structural AF and 168 age- and sex-matched controls were recruited. The rs5065 and -G664C ANP SNPs were genotyped.
  
  
  RESULTS
  The study population had a moderate-to-high cardiovascular risk profile with 86% having hypertension, 23% diabetes, 26% previous myocardial infarction, and 23% left ventricular systolic dysfunction. Patients with AF had greater left atrial diameter (44 ± 7 vs. 39 ± 5 mm; P < 0.001) and higher plasma NTproANP levels (6240 ± 5317 vs. 3649 ± 2946 pmol/mL; P < 0.01). Odds ratios (ORs) for rs5065 and -G664C gene variants were 1.1 (95% confidence interval [CI], 0.7-1.8; P = 0.71) and 1.2 (95% CI, 0.3-3.2; P = 0.79), respectively, indicating no association with AF. There were no differences in baseline clinical characteristics among carriers and noncarriers of the -664C and rs5065 minor allele variants.
  
  
  CONCLUSIONS
  We report lack of association between the rs5065 and -G664C ANP gene SNPs and AF in a Caucasian population of patients with structural AF. Further studies will clarify whether these or other ANP gene variants affect the risk of different subphenotypes of AF driven by distinct pathophysiological mechanisms.
authors.affiliation: Cardiology, Department of Clinical and Molecular Medicine, St. Andrea Hospital, Sapienza University, Rome, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Francia
authors.forename: Agnese
authors.initials: A
authors.lastname: Ricotta
authors.forename: Alessandra
authors.initials: A
authors.lastname: Frattari
authors.forename: Rosita
authors.initials: R
authors.lastname: Stanzione
authors.forename: Anna
authors.initials: A
authors.lastname: Modestino
authors.forename: Federico
authors.initials: F
authors.lastname: Mercanti
authors.forename: Carmen
authors.initials: C
authors.lastname: Adduci
authors.forename: Isabella
authors.initials: I
authors.lastname: Sensini
authors.forename: Maria
authors.initials: M
authors.lastname: Cotugno
authors.forename: Cristina
authors.initials: C
authors.lastname: Balla
authors.forename: Speranza
authors.initials: S
authors.lastname: Rubattu
authors.forename: Massimo
authors.initials: M
authors.lastname: Volpe
keywords: atrial fibrillation; atrial natriuretic peptide; gene variants